Genome Wide Association of Many Diverse Phenotypes in Nitrogen Limited
Field Conditions
Andrew Leakey
Department of Plant Biology, Department of Crop Science, Institute for Genomic Biology, University of Illinois at Urbana-Champaign, Urbana IL, Department of Plant Biology, Department of Crop Science, Institute for Genomic Biology, University of Illinois at Urbana-Champaign, Urbana IL
Author ProfileAshish Rajurkar
Department of Plant Biology, Department of Crop Science, Institute for Genomic Biology, University of Illinois at Urbana-Champaign, Urbana IL, Department of Plant Biology, Department of Crop Science, Institute for Genomic Biology, University of Illinois at Urbana-Champaign, Urbana IL
Author ProfileAbstract
Nitrogen inputs can be an important cost consideration for farmers in
terms of economic profit as well as environmental impact. Elucidating
genetic regions that are associated with plant phenotype response to
nitrogen stress can help in facilitating breeding approaches that can
mitigate these costs. A diverse population of 272 maize lines was
planted at a field site in Champaign, IL in two consecutive years in
reduced nitrogen conditions. 302 phenotypes were recorded including:
seed ionomic content, root structural traits derived from 2-dimensional
images as well as a 3-dimensional representation generated from x-ray
computed tomography (XRT) scans, root traits extrapolated from
mini-rhizotron systems, drone images across the growing season and end
of season agronomic traits such as biomass and yield. BLUP models were
fit to obtain estimates of single year genotypic values as well as
across years values both of which took into account year specific
spatial variation. Individual years and combined years BLUP values were
used as response variables in genome wide association studies (GWAS) to
identify loci significantly associated with each set of values.
Significant associations were identified for all phenotype categories.